gigabyte gtx 670

Hi guys i was want to buy a dell [Precision] t3500 because it's cheap and have good performance so this will be the details: CPU:xeon w3530 or w3565 or 3680 PSU:525 W GPU:gigabyte gtx 670 2gb 3x windforce Ram :6 or 8 So what is the best spec that i choose? And that will make a bottleneck or...